1. Field of the Invention
The present invention relates to an ink composition for a color filter, a color filter substrate manufactured using the ink composition, a method of manufacturing a color filter substrate using the ink composition. More particularly, the present invention relates to an ink composition for a color filter capable of preventing an ink bleed at a surface of an ink-jetting nozzle and a surface of a black matrix of a color filter substrate. In addition the present invention relates to color filter substrates having improved thermal endurance and chemical resistance over conventional color filter substrates, as well as to methods of manufacturing a color filter substrate using the ink composition.
2. Description of the Related Art
Electric display devices are becoming more important as a visual information transmission media, as evidenced by their wide application in various industries. Novel electric display devices having novel functions that correspond to the demands of the information society are continually being developed.
In general, an electric display device converts electric information into an image. The electric display device is classified as either an emissive display device displaying an image using a light emission, or a non-emissive display device displaying the image using optical properties such as a reflection, a scattering, an interference, etc. The emissive display device may be referred to as an “active display device”. Examples of emissive display devices include a cathode ray tube (CRT), a plasma display panel (PDP), a light emitting diode (LED), an electroluminescent display (ELD), etc. Examples of non-emissive display devices as a positive display device include a liquid crystal display (LCD) device, an electrophoretic image display (EPID), etc.
The CRT, is one of the conventional display apparatuses used in image display instruments such as a television set, a computer, etc., and is widely used due to its display quality and low price. However, there are certain downsides to the CRT such as for example, it's heavy weight, large size, high power consumption, etc.
Therefore, electric display devices that are small in size and lightweight are highly desirable. Due to advances in semiconductor technology display devices including a flat typed panel that have characteristics such as thin thickness, low driving voltage, low power consumption, etc., are currently available and in high demand.
The LCD is a highly popular flat display device. The LCD device is thinner, has lower driving voltage and lower power consumption as compared to the CRT. Moreover, the LCD device also has an image display quality substantially the same as the CRT. The LCD device can also be easily manufactured, to thereby expand its applications in various areas.
The LCD device includes color filters such as a red color filter, a green color filter, a blue color filter, etc., to express a color image.
In order to manufacture a color filter, various processes have been applied to replace conventional photo lithography processes. One such process, is an ink jetting process employed to manufacture the color filter. According to the ink jetting process, a light-blocking layer such as a black matrix is formed on a glass substrate, and then the light-blocking layer undergoes an exposing process, a developing process to form a pixel area on the blocking layer, and ink is then injected into a pixel area to form the color filter. In addition, with the ink jetting process, additional processes such as a coating process, an exposing process, a developing process, etc., are not required to form the color filter, thereby the ink jetting process provides a simpler, less costly process, requiring less materials than other color filter manufacturing processes.
Further, with the ink jetting method, a color layer should be uniformly formed on each of the pixels so as to have a great color property. However, when ink overflows from a pixel on a color filter substrate, the ink is spread to the black matrix and neighboring pixels to contaminate neighboring pixels on the color filter substrate. Moreover, when the ink is jetted from an ink-jetting nozzle, the performance of the ink-jetting process mainly depends on a relationship between the ink and the ink-jetting nozzle. In particular, in the case where the ink is largely wetted to the surface of the ink-jetting nozzle, the jetting of the ink may not be straight or the ink cannot be jetted from the ink-jetting nozzle.
Thus, it is desirable to have an ink composition for a color filter capable of preventing an ink bleed when manufacturing a color filter substrate and which also improves the straightness of the jetting of the ink through an ink-jetting nozzle.